


Saber's Massive Mushy Master

by Gothdresser



Category: Fate/stay night - All Media Types
Genre: BBW, Big Beautiful Woman, Diaper, F/F, Fatty - Freeform, Pantypoop, Pee, Saber in a suit, Soiling, Urination, cumming, diapered facesitting, diapermessing, facemessing, facesitting, layering, messing, pantsshitting, pissing, pooping
Language: English
Status: Completed
Published: 2019-12-21
Updated: 2019-12-21
Packaged: 2021-02-25 20:34:09
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,781
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21881596
Author URL: https://archiveofourown.org/users/Gothdresser/pseuds/Gothdresser
Summary: And to complement Illya's birthday story, Saber finds herself with a new master, although the same master she once feared in the fight against Bahsaka, the little girl is not as little as she once knew. With the use of a couple of command seals, Saber is sure to grow to love her new master's big mushy tush~A bit of a way to make up for taking a whole extra month after Illya's birthday to finish her story, and hopefully this addition is big enough as it puts the combined stories over 10k words!~Enjoy~
Relationships: Illyasviel von Einzbern & Artoria Pendragon | Saber
Kudos: 13





	Saber's Massive Mushy Master

Watching the faint light on her hand grow slightly dimmer than before, Illya flexed the sausage rolls that she called fingers and smoothed out her shirt that already had trouble reaching her belly button before looking back at her new servant. Poor Rin had exhausted her command seals and Sakura already had Rider to deal with, leaving one cute little girl to swoop in and form the contract that Saber needed to remain in the world. Or well, maybe one not-so-little girl. While she was very small and petite during the Grail War, a lot of sweets and the stress of having lost caused Illya to indulge just a little too much, so much that now Sella was having trouble buttoning up her shorts.

A whopping 200 pounds too much as that was what she roughly weighed at this point, resulting in the inconveniences that a young girl might have with carrying around that much weight. It happened more often than not that Illya found herself no longer needing the toilet as she was on the way to the bathroom, yet instead of seeking a change, she got used to filling her underwear more. It was just so much more convenient to her, and it wasn’t like Sella wasn’t waiting on her hand and foot, or more like butt and underwear in this case with all the daily changes she got to enjoy by her maid’s hands.

Now, with the blonde-haired king of knights before her, dressed in a dark grey suit, Illya giggled as she watched Saber try to resist the command. A long-term command seal would be easier for her to struggle against, but the definite command that Illya had burned a seal on was much too potent. Try as she might, even Saber couldn’t help but break as her hands pressed into Illya’s overweight stomach, her fierce expression melting into one of pure bliss while her face planted into the rotund belly.

Blushing incredibly at even the idea that she was reduced to something so base, Saber found her will to withstand the humiliation washed away by the pleasure of feeling Illya’s stomach. “Gah…!” Hearing the command was bad enough, but to think the effects of the order were so strong, that her master would degrade her by forcing her to be unable to resist the appeal of a big beautiful loli. Her current master was the largest she had ever been contracted to, while Saber had known her much thinner but taller mother, although it wasn’t like this was the first thing that the Einzbern family had imparted upon her.

Illya did have to admit that her decree was finding its way to backfire on her, letting out a low moan while Saber groped and rubbed her stomach. It just felt so… s-so… uh oh… Eyes blinking a couple of times in surprise, Illya hadn’t even noticed the need before her big fat asscheeks began to spread, a thick mess pouring out of her overweight loli butt. Her moaning from before evolved into groaning as she felt her abdomen rumble against Saber’s face, rude noisy sounds erupting from the large rear that filled her panties up almost to the brim. The squishing of her stomach resulted in so much squishing in her panties, the big mess sandwiched and smushing between the brown bulging buttcheeks of her big loli rear. “E-eh?... Nooooo, I wanted you to change me into a diaper first, come on…” The pouting of her chubby cheeks quickly turned into a smile as while Illya had already messed herself, that didn’t mean she had to be the only one with poopy panties. Raising her hand up again, two seals were imprinted on the back, the glow growing just slightly dimmer once again as Illya uttered, “Saber, I command you to poop yourself when I order you to!”

Stepping away from Illya, the King of Knight’s eyes flashed in surprised at yet another odd command, a stark difference from the girl’s father who ordered her to destroy the Holy Grail. Her sly smile had to be hidden though even if Artoria could not prevent a blush from surfacing from her face. “M-Master, please tell me you’re not serious. How could you ever give such a depraved and naughty order to a just king such as myself? To think my knights would weep if you ever u-used such a command… Just whatever you do, Master Illya, I could think of nothing more shameful than to feel a big mushy mess in my panties just fill it… U-uh, ha…” Trying to excuse away her awkwardness before she delved into more of that fantasy, Saber felt the front of her panties tighten, not only from how tight the pants of her suit were but a different familiar sensation. While Kiritsugu had only ever said three things to her, Irisviel was a million and one times more personal, much to Saber’s chagrin as she tried to keep a straight face before her massive messy master.

Illya had expected a different reaction from Saber, something more scared or desperate given that the safety of her pants was on the line, although she would just have to do without that certain satisfaction until Saber learned just how serious the not-so-little girl was. “Hmm hmm hmm, oh, what to do~ I do need a diaper, but I think that can wait a moment as I order you to poop your pants, Saber. Now!” While a mess had flooded out of her big jiggly loli butt, smugness filled Illya up now as she watched Saber grip the sides of her stomach, the proud King of Camelot reduced to nothing more than a pantsshitter.

Gritting her teeth, Saber was fighting a different battle than the one Illya thought she was as her stomach began to feel overly-full all of a sudden, with an intense pressure in her abdomen begging to burst just as something else in Saber was. Gulping down once more as she tried to resist it, the command seal’s magic was too powerful for her magic resistance as crackling returned to the air between Saber and her master. “A-ah no, please, I would never ever want to defecate myself, n-never…!” Such a well-dressed outfit was quickly ruined as a thick log of shit spread Saber’s asshole wide, tenting the back of her pants slowly at first before a distinct fart preceded the rest of the mess to burst into her underwear, the gross sound of a big load of shit pushing and packing a pair of panties to fill every little bit of available space.

Illya couldn’t help but giggle as she enjoyed watching Saber grunt and groan and moan to the tune of emptying out into her underwear, the small cotton panties no doubt needing to be thrown out even after a single mess. For how much Artoria was pooping herself, Illya almost expected her bladder to let loose as well with the release of such pressure, leading to something she didn’t expect at all. The sound of soiling was dying down, but Illya heard another squish as she watched Saber’s hips bucking before something other than pee spurted out through her pants.

With her servant panting before her, the lardass loli was at a loss for words, more than old enough to know that Saber hadn’t just peed herself, but rather… “Saber, why did you… huh?” She could connect the dots of what it could be since it wasn’t like she herself was in no way immune to stickier fun because of her accidents, and yet the thought of Saber, of all people, cumming to pooping herself felt all too unlikely.

“So you noticed, I see... “ As if anyone wouldn’t notice Saber’s pride going down the drain as she not only soiled her pants but ejaculated to doing so as well. Even the thought of that shame made her little Excalibur twitch in her panties, squishing coming from her loaded underwear as Saber nervously squirmed a tad. “Your mother has quite the way with people, especially since like you, she was my master in more ways than one. It appears even though I was summoned again, I still have some after-effects of her training.” Countless instances of being summoned, and yet all it took was Iri to corrupt her like this, a depraved set of fetishes that Saber couldn’t say she wasn’t happy to have now.

The thuds of obese footsteps heavy on the ground accompanied the squishing of Illya’s rear as she walked around her servant, her eyes drawn to the large mess clinging to Saber’s butt that rivaled Illya’s own in proportion. Such strong bowels for a servant and Illya pulled the back of Saber’s pants out as she stopped behind her for a moment. “Ah, so Mama is responsible for this~ Hehe, I remember seeing Papa or a maid change her after she changed me. Sounds like you both did a lot while you were here in Fuyuki! Guess we’ll have to make up for that, won’t we, Saber?~”

Moving back around to the front of her servant, Illya turned around before bending over, her arms not even able to reach anywhere near her toes but she gave quite the view of her shitty shorts to the servant. Wiggling her big brown bulbous butt right up against Saber, she looked behind her as well as she could to watch Saber’s reaction. “Judging by your pants, we both need a change. You wouldn’t mind doing that for me, would you? Ah ah, but no touching unless you accept~”

Feeling her little thing tighten at the squishiness of the big fat messy butt against her, Saber had to watch her breathing as she followed Illya’s order, holding her hands back despite how much she wanted to mush and grope such a large mess. “J-just a change, right? How could I say no when your rear is even bigger than your mother’s. Please, my master, I’ll change you and your knickers as much as you like, anything for a butt like yours.” Resisting the impulse to start playing with the large stinky rear felt nearly impossible to Saber, somehow controlling herself just barely.

“And my diapers as well, you’ll find a change in the bag and then you can have your fun. As much as my servant likes, don’t hold back~” Gesturing over to a purple bag, Illya felt the moment of hesitation as Saber had to disconnect herself from the poopy panties before watching her knight squish her way over to it. It was almost like Saber was handling a bomb with how unsure she seemed, slowly unzipping it to reveal quite the cache of supplies. Most importantly, an XXL diaper was unsheathed from it, the size and thickness of just one diaper made Saber’s girlish hands look much smaller. “Mmhm, all you need to do is change me into one of those~” Such a heavy stinky butt slowly squatted down to the floor with a drawn-out squish as Illya felt all that mess squish up and against her ass, her buttcheeks full of the shit that her panties struggled to keep it in.

Squeezing the soft padding to hear the crinkling, mushing is what attracted Saber’s attention now as sitting down on top of the mess made it look even larger. “Right away, Master.” Composing herself as well as she could with such a mess presented to her, Saber grabbed the supplies but stopped herself before she moved back to Illya, grabbing an additional diaper as well. It almost felt like a shame for Saber to change such a messy rear, giving it a few squishes before removing the thoroughly-packed shorts and panties. With almost all of the mess in the panties, it was a miracle that Illya’s fat loli ass was somewhat clean, giving her a quick clean-up job with the wet wipes.

Saber finally slid the first diaper under the heavy butt, lifting up Illya’s chunky stomach to tape the padding up and following the same procedure with the second diaper. “There you go. I’ve finished changing your nappy, Master, and I even gave you a second one so you can stay in that one longer.” Although that was more for herself than for Illya to give her more time to enjoy that big fat little girl butt after it blew up her plethora of padding.

Illya almost enjoyed the jiggle of her butt as she shivered from the sensation of the cold wet wipe on her skin, the towelette always doing a good job of wiping away all that ickiness. It even tickled her butthole a bit as Saber did quite a thorough job, ultimately leaving her in the thickness of two layers. Sella only ever put her in one despite the Einzbern fortune easily being able to afford more, and the struggle to currently sit up made Illya curious about a third layer or more. “Good work, now lie down and I’ll give you your reward, Saber~” Somehow getting to her feet, Illya pointed a chubby digit towards the floor that she just got off of.

With her master left only in her ill-fitting tank top and the double diapers, Saber quickly took her place, listening to the squishing of her own rear as it smushed against the ground and mushed between her asscheeks. There was a moment of apprehension as she lay there on the floor for what Illya would do, something that was quickly answered as the fatass managed to waddle her thick padded rear right over Saber’s face. In but a moment, the King of Knight’s face was eclipsed by the massive overweight diaperbutt.

One diaper was a soft enough seat already, but the second one only crinkled louder as Illya relaxed onto Saber’s face, letting off quite the load after all that struggle to stand up in the first place. That wasn’t the only load as not long after she shifted all that weight onto Saber, her tummy gurgled and let out a soft fart, doing her best to hold off just barely. “Ah, my servant makes for such a nice seat. Wouldn’t you agree, Saber? Make sure to speak up~” Listening closely, Illya could hear just the faintest muffling from underneath her diaper, although that was quickly swallowed up by quite the rude sound.

Gurgling turned to crackling that turned to the combination of squishing and crinkling as Illya’s explosive rear burst and her fat loli ass blew out her diaper. Anything that Saber was saying was overshadowed by the sounds of the overweight little girl ruining her diaper not even five minutes after it had been changed. And if the feeling of releasing yet another giant load wasn’t good enough, Illya grinded back and forth in her diaper as she watched Saber’s hips buck. It was hard to see over her large stomach, but the knight made the effect of the messy fatty facesitting quite obvious.

More so as Illya watched Saber’s little saber burst through her pants again, a larger reaction than before while Illya felt her own breath hitching. Within a matter of seconds, groaning burst out of Illya as she felt her little cock finally squirt, another torrent of mush squishing out of her thick fatty asscheeks. Even just beginning to train Saber already felt this amazing, and the not-so-little girl knew that this wasn’t going to be the last time they had this fun.

Slowing her grinding down, Illya did her best to catch her breath as she lifted her heavy arm to rub her eyes. So much work already after playing with her servant and pooping her double diaper, leaving Illya to start shifting backward. She let her legs straighten out as she lay down on her back, the massively messy padding still piled atop Saber. The shifting under her poopy butt was a slight annoyance though while she tried to get comfortable. “I’ll get up after a quick nap, Saber. You put me in two diapers anyways, so I won’t leak… hopefully, hehe~”

The Einzbern’s white greater grail relaxed against the floor, and within minutes, the King of Knights’ struggling under Illya’s stinky crinkly butt was deafened by soft snoring and hissing. For such a strong servant, she was feeling weakened by soiling and cumming so much herself, enough that pushing such a heavy girl with such a heavy diaper was proving troublesome. Following suit, Saber slowly stopped her endeavor as she grew limp under Illya, having passed out in a mix of panic and excitement due to huffing too much of the pampered poopiness that clung to Illya’s big fat loli ass.


End file.
